Wednesday, December 9, 2009

As of Dec 4, 2009, the following was released by Molecular Anthropology in the Genomic Era team which oversaw the 4th International conference of the series on DNA polymorphisms in human populations that took place at University La Sapienza - Rome from December 3 through to 5, 2009:

Human Y chromosomes belonging to haplogroup R-P25 are quite rare in Africa, being found mainly in Asia and Europe. However, a group of P25 Y chromosomes that are not defined by the presence of a downstream derived marker (the paragroup R-P25*) are found concentrated in the central-western part of the African continent, where they can be detected at frequencies as high as 95%. Phylogenetic evidence and coalescence time estimates suggest that R-P25* chromosomes (or their phylogenetic ancestor) may have been carried to Africa by an Asia-to-Africa back-migration in prehistoric times. Here we describe six new mutations that define the relationships among the African R-P25* Y chromosomes and between these African chromosomes and previously reported R-P25 Eurasian sub-lineages. The incorporation of these new mutations into a phylogeny of the R-P25 haplogroup led to the identification of a new clade (R1b1a or R-V88) encompassing all the African R-P25*, about half of the few European/west Asian R-P25*, and the R-M18 chromosomes. A world-wide phylogeographic analysis of the R-P25 haplogroup provided strong support to the Asia-to-Africa back-migration hypothesis. The analysis of the distribution of the R-V88 haplogroup in more than 1,800 males from 69 African populations, revealed a striking genetic contiguity between the Chadic-speaking peoples from the central Sahel and several other Afroasiatic speaking groups from North Africa. The R-V88 coalescence time was estimated at 9,200-5,600 kya, in the early-mid Holocene. We suggest that R-V88 is a paternal genetic record of the proposed mid-Holocene migration of proto-Chadic Afroasiatic speakers through the Central Sahara into the Lake Chad Basin.

Cruciani is known for making observations that don't exactly match up with what his actual DNA results show. The present author pointed this out on this site with both R1*-M173 chromosomes, E-M78 clusters and E-M34. So, the present author now reiterates what's wrong with his so-called "Asia-to-Africa back migration", which he seems bent on promoting, since otherwise would implicate European ancestry directly from Africa, which is known to get Eurocentrists' and closet-Eurocentrists' pants in a bunch.

Previously, when Cruciani (2002) thought he had come up with undifferentiated, upstream Hg R1* chromosomes, he considered it a possibility that this could be suggestive of African origin, since the African counterparts were phylogenetically more basal than his non-African sample collection; yet, this didn't phase him to entertain the alternative then, about back-migration to Africa, predicated on a flimsy case about Hg R, in its entirety as a family, not being as diverse in Africa as it appears to be in Asia. At the time, this was essentially Cruciani's sole argument for his preference of a back-migration scenario, which obviously contradicted the fact then, that his African samples were the ONLY ones which tested positive for the most basal R markers.

So now, he comes up with new markers, and tries to see if he can solidify his earlier rather debatable, if not flimsy, position. But even here, having sampled a number of Chadic-speaking populations in the central Sahel as a gesture of applying fine-tooth combing to the DNA sequencing of the Hg R chromosomes, particularly the perplexingly-unique African examples, he points out that the Hg R chromosomes bearing the "new mutations" he tested for are still more prevalent in Africa, and rarer in non-African areas. Yet, Cruciani wants to convince us that this is some sort of unequivocal proof that Africans must have attained it from back-migration, and he tries to reinforce this effort, by invoking early Holocene estimation dates. Also, contrary to Cruciani's mindset, it is not necessary for *all* the sub-clades of K to emerge in Africa, in order for the origin of K-M9 on the continent to be probable. Hg K's most immediate descendants like Hgs T, K1, K2...etc do not form monophyletic branching with respect to one another, but each of them form their own distinctive branch from the ancestral K-M9 node. Nor is it even necessary for the M9 mutation to have emerged in Africa, in order for R to emerge in Africa; humans are not static creatures. All that is needed, is for the P clade to have been present in Africa at some point in time. To the present author's knowledge, P has not been uncovered as a standalone clade [lacking downstream markers] anywhere. However, it is interesting to note that African R1*-M173 chromosomes were previously tested for the P25 mutation, and came up negative. What does this then mean? It means that while Africans carried rare Hg R1 chromosomes bearing the P25 marker, they also carried examples without the P25 marker [see Hassan et al. 2008, for example]. In other words, African R1-bearing chromosomes aren't homogeneous as Cruciani would perhaps like us to believe.

Furthermore, as the present author has noted here and elsewhere before,...

Interestingly, upon revisiting Wood et al. (2005), it should be pointed out that paraphyletic clade of R*-M207 was detected amongst some "Afro-Asiatic" African groups, along with the paraphyletic clade R1*-M173 [it is worth noting that Wood et al. implicate the Egyptian sample here as something other than that of Semitic speakers (Arabic)], while some Niger-Congo groups — though in small frequencies [pooled] —tested positive for the paraphyletic R1b*, lacking the established downstream R1b markers. Henceforth, R*-M207, lacking downstream mutations have been identified in African groups via this study; and yes, the basic nodes of all presently known Hg R's downstream clades had been accounted for, which means that R*, as predicted above, is NOT relegated to the Indian sub-continent. All in all, this suggests that African Hg R pool is actually more diverse than many seem to think.

So once again, African R-bearing chromosomes lacking the P25 marker have been identified, whereas Cruciani's Hg R chromosomes all appeared to have tested positive for P25; his samples bearing the R-positive chromosomes only differed from subsequentdownstream markers - presumably aside from one or more of those "new mutations" that Cruciani claims he had used in his DNA sequencing. African chromosomes transcend even the ancestral Hg R1* marker; the paraphyletic R* is also implicated, which is ancestral to R1* marker!

...but the present author has a hunch that Cruciani isn't done fine-combing Hg R chromosomes just yet, if he is to unequivocally prove that back-migration scenario he seems to so desire. So, watch this space, and please go over the cited R1*-M173 link(s) again, as it is constantly updated!
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References*

Given the well-documented fact that human body proportions covary with climate (presumably due to the action of selection), one would expect that the Ipiutak and Tigara Inuit samples from Point Hope, Alaska, would be characterized by an extremely cold adapted body shape. Comparison of the Point Hope Inuit samples to a large (n > 900) sample of European and European- derived, African and African-derived, and Native American skeletons (including Koniag Inuit from Kodiak Island, Alaska) confirms that the Point Hope Inuit evince a cold-adapted body form, but analyses also reveal some unexpected results. For example, one might suspect that the Point Hope samples would show a more cold-adapted body form than the Koniag, given their more extreme environment, but this is not the case. Additionally, univariate analyses seldom show the Inuit samples to be more cold-adapted in body shape than Europeans, and multivariate analyses that include a myriad of body shape variables such as femoral head diameter, biiliac breadth, and limb segment lengths fail to effectively separate the Inuit samples from Europeans. In fact, in terms of body shape, the European and the Inuit samples tend to be cold-adapted and tend to be separated in multivariate space from the more tropically adapted Africans, especially those groups from south of the Sahara. - abstract ends

One excerpt from the study states:

There is strong evidence for such selection operating in the millennia following the initial appearance of modern humans in Europe, i.e., among Late Upper Paleolithic and Mesolithic Europeans (Holliday, 1999).

Specifically, the earliest modern humans in Europe for whom we have body proportion data tend to show more African-like body proportions (Holliday, 1997a), while later European modern humans show foreshortened limbs in spite of archeological data indicative of improved cultural buffering. This suggests selection for shorter limbs in Late Pleistocene Europe, although we also cannot as of yet rule out the possibility that late Pleistocene gene flow from Neandertals to early modern Europeans played some role in establishing more ‘‘cold-adapted’’ limb proportions for this latter population (Holliday, 1997a, 2006b).

Several issues stand out here: Fair enough, the earliest modern human evidence in Europe show "tropical African-like" body stature; however, here, we are told that evidence of "cold adaptation" starts to appear in the late Upper Paleolithic. Is it then safe to say, that while "tropical limb-proportions" has more than likely always been coexistent with considerable skin pigmentation, short index limb-proportions—as seen in Europe—are not as good as indicators of change in soft body phenotype, such as skin tone? If one goes by published journals from several skin tone analysts, it is hypothesized that the change in skin tone appeared to be marked by an episode of a selective sweep, likely some time close to the middle of the Neolithic (or early Neolithic in Europe) era [and the present author takes it that the suggested dates mainly correspond to contemporaneousEuropean archeological status quo, as the dates may vary from region to region according to state of then existing economy type]. Now remember, it is hard to determine the ages of skin tone alleles under selective pressure with any degree of certainty. One has to therefore infer that skin tone analysts turn to secondary disciplines, outside of genetics, to come up with their age estimations; such disciplinary candidate is archaeology [like those associated with Neolithic farming traditions] and possibly, its paleontology sub-discipline. Only here, human paleontology appears to be disconcordant with examples of such age estimations that come to attention.

Note that the authors indirectly insinuate that a scenario of descendance into poor dietary and life style, relative to the preceding epochs—which is lacking here, does not seem to be a factor in such change in body stature; see:

Specifically, the earliest modern humans in Europe for whom we have body proportion data tend to show more African-like body proportion (Holliday, 1997a), while later European modern humans show foreshortened limbs in spite of archeological data indicative of improved cultural buffering.

Could it then be inferred that change in skin tone very likely accommodated change in body stature, but that such change was gradual in its spread and not in the extreme states that we now see in European populations? And as follows, that the spread of Neolithic farming subsistence factored into a subsequent selective sweep, given Europe's latitudinal positioning? If so, then only here, without extraordinary visible distinctions between "would-be intermediary Europeans" [in terms of skin tone developments] and the more extreme cases of contemporary Europeans, in terms of human remains record, one is hard-pressed to discern between such changes in soft body parts like skin tone.

A look back at older publication from the same author implicated above—Holliday (1999)—suggests that very possibility, the transitory scenario mentioned in the winding comment of the last paragraph (above); here is a copy of the abstract:

Among recent humans brachial and crural indices are positively correlated with mean annual temperature, such that high indices are found in tropical groups. However, despite inhabiting glacial Europe, the Upper Paleolithic Europeans possessed high indices, prompting Trinkaus (1981) to argue for gene flow from warmer regions associated with modern human emergence in Europe. In contrast, Frayer et al. (1993) point out that Late Upper Paleolithic and Mesolithic Europeans should not exhibit tropically-adapted limb proportions, since, even assuming replacement, their ancestors had experienced cold stress in glacial Europe for at least 12 millennia. This study investigates three questions tied to the brachial and crural indices among Late Pleistocene and recent humans. First, which limb segments (either proximal or distal) are primarily responsible for variation in brachial and crural indices? Second, are these indices reflective of overall limb elongation? And finally, do the Late Upper Paleolithic and Mesolithic Europeans retain relatively and/or absolutely long limbs?

Results indicate that in the lower limb, the distal limb segment contributes most of the variability to intra-limb proportions, while in the upper limb the proximal and distal limb segments appear to be equally variable. Additionally, brachial and crural indices do not appear to be a good measure of overall limb length, and thus, while the Late Upper Paleolithic and Mesolithic humans have significantly higher (i.e., tropically-adapted) brachial and crural indicesthan do recent Europeans, they also have shorter (i.e., cold-adapted) limbs. The somewhat paradoxical retention of "tropical" indices in the context of more "cold-adapted" limb length is best explained as evidence for Replacement in the European LatePleistocene, followed by gradual cold adaptation in glacial Europe. - TW Holliday, Brachial and crural indices of European late Upper Paleolithic and Mesolithic humans, 1999.

In other words, the concluding portion of that abstract suggests that while the brachial and crural indices of the limb components reported relatively high scores—generally characteristic of those seen in populations inhabiting the tropics, the overall actual lengths of the limbs of the Late Upper Paleolithic and Mesolithic European specimens tend to be shorter in comparison to contemporary European examples. This means that recent Europeans would generally be considered taller in comparison to their said earlier European counterparts, notwithstanding the higher limb proportion indices characterizing the latter; in simple terms, one may interpret this seeming contrasting manifestations of limb proportions vis-a-vis overall limb length as suggestive of being part of a transitory phase towards gradual cold adaptation, as noted above. As to the question of the most probable state of soft tissue phenotype such as that of skin tone, one which would have been contemporaneous with the said Late Upper Paleolithic and Mesolithic physical states, one can only surmise some form of relaxation in epidermal melanin, without knowing the precise level; for instance, one might guess that it could have been along the lines of the Inuit, but then again, the Inuit are considered fully cold-adapted. So the question of skin tone is not clear here, and not nearly as neat as the correlation that can be made between tropically adapted body plan and the intense UV radiation levels of tropical latitudes.

And from the remaining segment of the first excerpt,...

This suggests selection for shorter limbs in Late Pleistocene Europe, although we also cannot as of yet rule out the possibility that late Pleistocene gene flow from Neandertals to early modern Europeans played some role in establishing more ‘‘cold-adapted’’ limb proportions for this latter population (Holliday, 1997a, 2006b).

If such event took place, i.e. gene flow between Neanderthals and early modern Europeans, then it appears that genetic drift had effectively sifted it out of modern human gene pool, almost akin to saying that the offspring emanating from such activity died out. On the other hand, molecular genetics presently rules out such undertaking, on the account of which, the analysts/authors here seem to be kept in the dark of.

Moving onto a second extract...

It has two main branches—a long and linear body build branch that includes the Egyptians, Sub-Saharan Africans (except for the Pygmies), and African-Americans and a second, less linear body form branch that includes the Inuit, Europeans, Euro-Americans, Puebloans, Nubians, and Pygmies. Note that the Nubians used in this study are thought by some to represent an immigrant population from Europe or Western Asia [see Holliday (1995)].

Well, it is not surprising to see ancient Egyptian specimens consistently group with sub-Saharan Africans, and not with Europeans, notwithstanding whatever supposed "caucasoid" archetype tendencies are said to be implicated in cranio-morphometric estimations according to some publications of the past, which are prone to inconsistency across different authors, because of variations in sampling selections to the discretion of the samplers. Several published journals have made note of this post-cranial feature of Nile Valley specimens, and they have been covered elsewhere on this blog.

However, the pygmies notably standout here in terms of body "linearity", given their traditional habitat in the African tropics of "sub-Saharan" Africa. Could it have anything to do with discordance between crural-brachial indices and "body build" brought about by their characteristic short height (in correlation to short limbs)? It certainly warrants further examination into the authors' findings and the premise thereof. Likewise the "Nubians", but explanation is offered here for the seeming anomaly. Funny thing about the latter, is the less likely inclination of fringe Eurocentric sects to seize on such isolated finding and use it to suggest that "Nubians" were primarily drawn from the "Nordic" or "caucasoid" stock.

On a winding note, there appears to be disconcordance between the post-cranial report from Holliday & co. (2009) and cranial report from Katerina Harvati (2009). As seen above, Holliday and co. deduced selection for shorter limbs in their late Upper Paleolithic European sample [as opposed to the earlier Upper Paleolithic European specimens], which is interpreted as a sign of "cold adaptation" to the temperate environment of Europe; whereas, Harvati's report shows closer positioning of both early Upper Paleolithic and late Paleolithic European specimens to modern examples from sub-Saharan Africa [Kenyan and South African, Zulu in particular] than they are to modern west European and north Levantine [Syria] counterparts. Now of course, we are looking at post-cranial analysis on the one hand, and a cranial one on the other; hence, precisely what sort of body proportions Harvati's late Paleolithic European specimens exhibited, is anyone's guess, unless data for such is made available. This disconcordance noted here though, as Holliday's 1999 study shows, is not total; after all, retention of "tropically-adapted" phenotype in the limb proportion indices is observed in the Late Upper Paleolithic to Mesolithic European specimens. That said, as a preliminary consideration, could the said contrast in reports from two different sections of human skeleton have something to do with that "gradual change" mentioned in the question put forth above? Perhaps the same question may be asked of the Zhoukoudian Upper Cave [in China] specimens, who are claimed to have close cranial affinities with the late Paleolithic European counterparts.

Naturally, this question makes sense, only if the said Harvati's late Paleolithic European specimens [the Zhoukoudian Upper Cave specimens as well] showed up body proportions consistent with observations made by Holliday et co. in their post-cranial analysis. However, it should be noted that the precise nature of the interplay of several different underlying factors behind cranial morphology is less clear than that underlying post-cranial skeleton, and while cranial morphology exhibits perhaps the most visibly diverse manifestations of hard human physical form, it is also more prone to overlapping [through happenstance in some cases, and gene flow in others] between a wide range of populations from across different latitudinal environments than the case is for post-cranial phenotype; for instance, specimens bearing tropical body-proportions in an unquestionably sub-tropical refugium serves as a fairly good indicator of a peopling event, shortly after emigration from a tropical environment. If Europeans' earliest ancestors came from a sub-tropical refuge center of a generally cool geographical clime of say, central Asia, then one would expect less inclination towards the display of tropical body proportions, having undergone some level of adaptation or another to the sub-tropical environment. On the other hand, certain crania from populations in the tropics have been inflicted with pseudo-scientific labels such as "caucasoid", even as the body proportions prevalent in those populations turned out to be markedly distinct from so-called "caucasoids" of temperate latitudes.

Thursday, November 26, 2009

Herein, aspects of a recent publication by E. González-Pérez et al. (2009) under the heading described above, will be revisited and examined respectively.

The abstract goes as follows:
González-Pérez et al.

Am J Phys Anthropol. 2009 Nov 16.

The variation of 18 Alu polymorphisms and 3 linked STRs was determined in 1,831 individuals from 15 Mediterranean populations to analyze the relationships between human groups in this geographical region and provide a complementary perspective to information from studies based on uniparental markers. Patterns of population diversity revealed by the two kinds of markers examined were different from one another, likely in relation to their different mutation rates. Therefore, while the Alu biallelic variation underlies general heterogeneity throughout the whole Mediterranean region, the combined use of Alu and STR points to a considerable genetic differentiation between the two Mediterranean shores, presumably strengthened by a considerable sub-Saharan African genetic contribution in North Africa (around 13% calculated from Alu markers). Gene flow analysis confirms the permeability of the Sahara to human passage along with the existence of trans-Mediterranean interchanges. Two specific Alu/STR combinations-CD4 110(-) and DM 107(-)-detected in all North African samples, the Iberian Peninsula, Greece, Turkey, and some Mediterranean islands suggest an ancient genetic background of current Mediterranean peoples. - abstract ends

Tandem Repeats linked to sites identified with specific Alu insertions or deletions designated by three designators: CD4+, DM+ and FXIIIB-. These reportedly represent the "ancestral" states of the sites in question, and the nature of said site-states are indicated by either the "+" or "-" symbols respectively.

Y-chromosome Alu insertion: The YAP+ Y-chromosome Alu insertion, fairly common in African populations, particularly in the form of Hg E, serves as an addition to the collection of Alu markers cited above.

Populations sampled:

Click on the image to get a better resolution.

The study opens with the following lines:

As far as the origin of human populations in the Mediterranean is concerned, it is commonly accepted that their roots can be traced back to the Upper Paleolithic with the expansion of human groups from the Near East or Central Asia, or some millennia later with the westward and northward spread of Neolithic populations from the Fertile Crescent. Although there is little doubt regarding the human entrance route to the Mediterranean, controversy appears when different studies try to determine to what extent their current genetic background preserves traces of Paleolithic people and in which degree the almost continuous cultural and political contacts have influenced present genetic affinities.

Indeed, the authors are correct in their assessment about controversy in terms of how different studies interpret their observations, with regards to the entrance or exit of certain lineages, particularly in relation to the time of event and how extensive. Their own opening assessment attests to this, recalling the bit about origins of "Mediterranean" populations being traced back to the so-called "Near East" or Central Asia. This implies that northern Africa was a barren region for a long period of time, where no autochthonous African population ventured, even as humanity spent the bulk of its socio-biological evolution exclusively on the continent until ca "50-60 ky ago era" when a subset of anatomically modern humans successfully left the African continent for refuge elsewhere. This begs the question: human beings in Africa did not see fit to populate the northern areas of the continent, yet non-Africans were supposedly the first to see fit to do so? As a matter of fact, Maghrebi paleontological record stretches back to as far as the Middle Paleolithic era, preceding anatomically modern human occupation outside of Africa.

The authors appear to have been influenced in their assessment by the likes of Olivieri et al. (2006), whose work has been a subject of discussion (clickable link) on this site, as it relates to the Upper Paleolithic demic diffusion episodes in the northern sections of the African continent, and by the likes of Arredi et al. (2004), as it relates to theories surrounding Neolithic demic diffusions in that same region. Apparently, the authors are working with outdated concepts in their assessment, as earlier theories about Upper Paleolithic northern African complexes [see for example, the so-called "Ibero-Maurusian"] being manned by people from outside of the continent, based on erroneous assumptions built around archaeological finds on lithic artifacts, have now been rectified and updated with research that link origins of certain Upper Paleolithic lithics-oriented innovations to northern Africa, which were subsequently diffused into neighboring extra-African territories. Other erroneous assumptions about the earliest Upper Paleolithic northern African anatomically modern populations coming from outside had been based on shabby and flimsy reliance on outdated bio-anthropological concepts built around cranio-morphometric examinations. A notable example that immediately comes to mind, is the idea of Mechtoid populations [see: Mechta and Afalou: Do they and the so-called "Mechtoids" constitute a type with the "Cro-Magnon"?] , who were almost considered to be synonymous with the Cro-Magnon of Europe. Outposts of lingering cult-like Eurocentric elements continue to rely on ideological concepts of the Cro-Magnon as some sort of embodiment of "Caucasoids" or "Caucasians", and even that, has been discredited by more recent and refined analysis of cranio-morphometric data [See: Brace et al. (2005) and Chris Stringer (click), for example]. Even earlier bio-anthropologists tacitly took note of differentiations between the African Mechtoid variants and those of the European Cro-Magnon, even as superficially-invoked links were being insinuated. The bottom line is that the authors' presumptuous assessment, that the theory of northern Africa being first populated by people from the so-called Near East is a "commonly accepted" understanding, has little basis to it, as no prevailing evidence backs up such a notion. It implies that this is an understanding that has harmonized the various scientific multidisciplinary applications at our disposal, when no evidence has been brought forth to suggest such status quo. It is certainly not the message harmoniously relayed by either genetics or paleontology, nor by Upper Paleolithic complexes, as just mentioned a few comments ago. Then by what, aside from wishful thinking? Notably, the authors' own data does not lend support to such thinking. On the other hand, the flaws of Olivieri et al.'s (2006) and Ana Gonzalez et al.'s (2007) Upper Paleolithic demic diffusion hypothesis have been touched upon on this site before. U6 is undoubtedly Upper Paleolithic by most accounts, but it makes up very little of the contemporary northern African gene pool, while major M1 expansions are mostly linked with spread of proto-Afrasan or Afrasan-affiliated speaking groups some time in the late Paleolithic and early Holocene Neolithic time frames. Again, Olivieri et al. (2006) are emphasized here, because the authors of the present study appear to be relying on them, with regards to so-called Near Eastern sourcing of Upper Paleolithic northern African populations; see for example:

Recent mitochondrial DNA data (Olivieri et al., 2006) suggest a common Levantine source for the Upper Paleolithic cultures that occupied the European (Aurignacian) and North African (Dabban) shores of the Mediterranean. A more recent origin for these populations associated with the demic diffusion of Middle Eastern groups in the Neolithic has been suggested by studies of Y-chromosome (Arredi et al., 2004) and autosomal data (Myles et al., 2005; Tomas et al., 2008).

The authors of the present study themselves reference research that contradicts the idea of either the Upper Paleolithic or Neolithic sourcing from the so-called Near East; see for example:

A detailed survey of the E-M78 Y-chromosome haplogroup (Cruciani et al., 2007) indicates the Northeast African origin of this variant and its involvement in trans-Mediterranean migrations from North Africa to Europe during the last 13,000 YBP.

The predominant paternal markers of coastal northwestern-central African markers are comprised of E-M78 and E-M35 markers. This being the case for the northern African populations that the authors sampled here, the fact serves as a major contradiction to the so-called Near Eastern sourcing of northern African populations, who have supposedly persisted into contemporary times, if we are to go by conclusions drawn by the authors of the present study. Yet, we are suppose to buy into some presumption of the Upper Paleolithic "Near Eastern" sourcing of northern African populations as some sort of a "commonly accepted" understanding or truth.

It should be reiterated, as explained before on this site, that contemporary Imazighen-groups , who predominate much of northern Africa today, don't have TMRCAs—deemed to be "characteristic" of Tamazight or "Berber" speaking populations—that date to the Upper Paleolithic. Yes, these lineages derive from lineages of Paleolithic provenance, but they themselves, don't—at least not according to patrilineal lineage. The E-M81 mutation of the E1b1b lineage—which is predominantly found in Imazighen populations—has at most, been implicated in expansions that only go back as far as 8 ky or so ago. This falls short of the ages associated with Upper Paleolithic/Epi-Paleolithic or earliest Holocene cranial specimens uncovered in coastal northwestern Africa. Furthermore, none of the cranial specimens tied to contemporary northern African populations remotely tie in with the Cro-Magnon specimens of Europe, as Brace et al. (2005) had found out; whereas we are pressed to believe in ties between the so-called Mechtoid variants and the European-based Cro-Magnon.

Furthermore, the authors note:

Similarly, specific Mediterranean haplogroups or clades (U6 and M1b in the mtDNA; EM78 and EM81 in the Y-chromosome) have also been described for these populations and dated in Paleolithic times.

Nothing in the above supports "Near Eastern" sourcing of northern African populations examined here. None of the above markers are known for being quintessential indications of "Near Eastern" ancestry, as opposed to African ancestry. Not even U6, whose "non-African" ancestor remains ever so elusive, is a marker of the so-called "Near East"; it is quite rare in that region and its presence there can only be spoken of, in terms of back-migration from northern Africa, even if it is assumed that a proto-U6 ancestor was "Near Eastern" in origin. None of the markers above are even confined to the "Mediterranean" regions, so as to justify the use of the moniker of "Mediterranean haplogroups or clades".

One issue that stands out like a sore thumb, is the comprehensiveness of the authors' so-called "sub-Saharan" collection; see:

In search of new insights into these questions, this study analyzes a relevant set of Mediterranean populations including eight European samples (from Spain, France, Greece, and Turkey), seven from North Africa (Morocco, Algeria, and Egypt), plus two samples from Central Europe (Germany) and sub-Saharan Africa (Ivory Coast) as external references.

Granted, the Ivory Coast sample is representative of sub-Saharan gene pool, but it only serves as a part of that gene pool, not the whole of it. It is highly questionable that this Ivory Coast sample will contain all that that is present in sub-Saharan Africa, as opposed to giving a snapshot of what is present in sub-Saharan Africa. Furthermore, what purpose does it serve, to ignore populations situated between Ivory Coast and those in the northern African territories sampled? Common sense intimates that such an undertaking will ensure more abrupt changes in DNA marker distribution trends; but then again, the authors could be gunning for just that. From their frame of thinking, such relative abrupt change in pattern could serve to sift out what they think could be representative of the autochthonous northern African patterns. After all, the authors reckon:

This pattern identifies Mediterranean populations as genetically separate from both sub-Saharans and Central Europeans and allows the identification of a certain genetic structure between the two shores of the Mediterranean region.

There is still a problem with that perception, because while genetic exchange is expected between coastal northern African and the more-inward African populations, their primary ancestry has been liked to northeastern Africa [the Sahel region or southern confines of eastern Sahara; in other words, the belt or areas that seem to have been neglected in the study] and ultimately sub-Saharan eastern Africa. Certain information is bound to escape the authors' observation, with such sampling choices. Let's examine the sampling particulars, visually:

Click on the image for better res.

It is highly questionable that the Ivory Coast sample will be representative of all that which is part of the southern Sahara or Sahel belts. It is any wonder the Siwa sample assumed an "outlier" position on the authors' admixture analysis mapping, even though the Siwa, like the rest of the northern African populations sampled, are largely Imazighen and also live on the coastal areas of northern Africa. The Siwa sample noticeably maintains a good deal of distance from the Ivory Coast sample as well, not withstanding observations that sub-Saharan gene flow appears to be most significant amongst them vs. the other northern African samples.

This sampling choice might account for the seemingly discordant observations in the 18 Alu "admixture" estimations and that of the Alu-STR combination "admixture analysis". The authors note:

In this general view, it is worth noting the particular position of two populations (the Spanish Pas Valley and the Egyptian Siwa Berbers) (see Fig. 2). These two populations have previously been described as genetic outliers (Esteban et al., 2006; Moral et al., 2006; Coudray et al., 2009) due to the orography of the Pas Valley and the desert surrounding the Siwa Oasis. This isolation could explain their differentiation by the action of the genetic drift associated with episodes with low effective population size, which in the case of Siwa Oasis, could have enhanced the effect of sub-Saharan flow (51% from Alu/STR data) through the Nile River (Fakhry, 1973).

Assuming one went by the earlier theory of the so-called Near Eastern Upper Paleolithic origin for coastal northern African populations, shouldn't the basic genetic structure of these populations therefore be the same, even when the effects of genetic drift are accounted for? Not only does the Siwa sample cluster away from the lone sub-Saharan sample of Ivory Coast, but also considerably does so from the coastal north African bunch, just going off on the 18 autosomal Alu markers alone...

MDS representation of the genetic distances (see Fig. 2) based on autosomal Alu data stresses the main differentiation of sub-Saharans, the clustering of Mediterraneans in two different groups corresponding to northern and southern populations, and the distant position of the Egyptian Siwa and the Spanish Pas Valley samples from their corresponding population clusters. The Siwa oasis sample presents a relatively extreme position, with respect to the other populations. In fact, the first genetic boundary in the Mediterranean separates Siwa Berbers from all remaining groups.

Furthermore, if "sub-Saharan" gene flow was able to reach the Siwa, then how could they be considered "isolated"? Certainly the desert areas in northern Africa have not "isolated" the other coastal northern African groups. "sub-Saharan" gene flow reportedly finds expression in many of the coastal northwestern African Imazighen populations sampled, as reaffirmed by the pattern seen in the Alu-STR clusters; however, we are told that in the Siwa sample's case, "sub-Saharan" gene flow is virtually negligible in Alu pattern alone. Yet, the same Siwa sample is supposed to be indicative of the highest "sub-Saharan" gene flow amongst the coastal northern African Imazighen groups, going by STRs linked to certain Alu sites.

As for individual populations, the sub-Saharan gene flow in North Africa based on the Alu data collection ranges between 6 and 17% (Table 3), except the Siwa Berbers where that influence was negligible. Admixture values based on Alu/STR combinations indicate that sub-Saharan flow in North Africa ranged from 16% (North East Moroccan Berbers) to 35% (remaining samples) with the exception of Siwa Berbers who showed the highest admixture value (51%).

How was the relatively lower "sub-Saharan" contribution able to find expression in Alu markers of the other coastal northern African populations, but the more significant "sub-Saharan gene flow"— as communicated in the Siwa Alu-STR combinations— almost not represented at all in the Siwa Alu markers alone? Are we to assume that genetic drift enhanced "sub-Saharan" STR patterns but minimally did the same for Alu markers? The authors attribute this phenomenon of their finds in the following manner:

The disparity between the results from Alu loci and Alu/STR haplotypes, apart from the potential effect of the different number of independent markers examined (18 vs. 3), could be related to different mutation rates and therefore the power to detect ancient or more recent demographic events. Similar disparities between these two kinds of markers were found in the admixture analysis (Table 3).

Now of course, only three types of autosomal Alu loci were selected for examination along with flanking STRs, which tells us little about change in mutation rates across the genome types used here, and to what extent STRs on the other locations are useful enough in determining gene flow, along with whether this is in line with the data provided by the three type of sites used here. Undoubtedly different mutations rates between STRs and Alu markers could be a factor at some level, but the pattern we see in the extent of "sub-Saharan" gene flow across the full range of markers used in this study, may be more explainable in the sense, that 1) if the Siwa sample sufficiently comprised of identical Alu markers on chromosomes that share their immediate TMRCA nodes with sub-Saharan counterparts, then it could be distributed in such a way that it would be hard to ascertain gene flow from "sub-Saharan" populations with any degree of precision, or 2) some differentiation in Alu allele representation and nucleotide manifestation could be the product of within-population mutational events of markers with a "sub-Saharan" background in the Siwa, possibly in an interplay with that "action of genetic drift" that the authors mentioned in a piece cited above and some level of external gene flow from neighboring non-African territories, or yet 3) if the basic genetic structure of the Siwa stemmed from a non-African source, but then got introduced to "sub-Saharan" gene flow in an ancient period, and the population had since then remained relatively isolated from such influences ("sub-Saharan"). Only here, in either scenario, some visible level of Alu allele similarities would have come to the surface within those samples that reportedly tested positive for said "gene flow".

The first scenario doesn't seem to be likely, based on the 18 Alu makers multidimensional plot, given the position the Siwa sample assumes. While the third scenario could be presumptuously insinuated from the 18 Alu markers plot, given the considerable distance between the Siwa and that lone sub-Saharan African sample from the Ivory Coast, not to mention the possible case of the relative narrower distancing from the European clusters when compared to the African counterparts, including the so-called "southern Mediterranean samples" (coastal northern African samples), it is doesn't seem likely either; why? One would have to assume that while the Siwa might have been introduced to "sub-Saharan gene flow" at some point in time, it would have likely been a very occasional affair, and/or a very ancient one in the ethnogenetic history of the population, because this gene flow would otherwisenot be negligible from across just the 18 Alu markers standpoint, even if the Siwa were of a small effective-population size subjected to heightened "action of genetic drift", and would therefore find expression as it did, in the other coastal northern African samples and European counterparts. Furthermore, the problem with that assumption is that the Siwa would likely have assumed a position more extreme than that of the "northern Mediterranean" samples in the 18 Alu markers multidimensional plot, from the lone sub-Saharan sample of Ivory Coast. The reason for this, is that elements of the "northern Mediterranean" samples would have become continued recipients of "sub-Saharan gene flow" either directly from sub-Saharan emigrants, and/or indirectly through continued contact with the "southern Mediterranean" populations aka coastal northern Africans. So the inclination here, is to go with the second scenario, and here's why: If the range of Alu markers were one or several step derivatives of autochthonous African counterparts, developed within the Siwa population during its ethnogenesis, then naturally, these markers would stand in contrast to ancestral sub-Saharan counterparts. As such, one would expect some level of persistence in some areas of the genome type selected for this study, particularly given that the sites that were picked for STR analysis happen to be those under linkage disequilibrium, according to the authors. So, while subsequent "sub-Saharan gene flow" cannot be ruled out in this scenario, it need not be the sole explanatory factor for the sub-Saharan inclinations of Siwa Alu-STR combinations, i.e. if the Siwa were treated as group that has been socio-culturally isolated from other external groups for some reason or the other. Possible additional external gene flow from nearby "non-African" territories, again likely ancient, cannot be ruled out under this scenario, in which case, such element would only serve to further contrast the Siwa Alu distribution from the sub-Saharan counterpart examined here...

The Siwa oasis sample presents a relatively extreme position, with respect to the other populations.

Under this scenario (2nd scenario), one can see why the so-called "southern Mediterranean" samples would assume intermediary positions along both types of multi-dimentional plots provided by the authors. The polarity here likely stems from a mix of continued, and hence more recent gene flow from external populations both African and non-African, along with in situ autochthonous within-population evolutionary events in said "southern Mediterranean" populations. Either of these factors would ensure that their socio-cultural and geographic distance from the Siwa would contribute to the differentiations in general Alu marker genetic structure, while at same time clustering them away from European clusters and the lone sub-Saharan sample. See:

the clustering of Mediterraneans in two different groups corresponding to northernandsouthern populations, and the distant position of the Egyptian Siwa and the Spanish Pas Valley samples from their corresponding population clusters.

Furthermore,...

This pattern identifies Mediterranean populations as genetically separate from both sub-Saharans and Central Europeans and allows the identification of a certain genetic structure between the two shores of the Mediterranean region. This genetic picture of populations may be related to geographic factors as indicated by the high correlation (P < 0.002) between geographic and genetic distances (based on Alu markers) found under the isolation by distance model. The genetic distinctiveness of Mediterranean populations, as well as the distinction between Northern and Southern Mediterraneans, coincides with results in previous studies (see for instance, Simoni et al., 1999; Comas et al., 2000; Boschet al., 2001).

Furthermore...

The estimates of sub-Saharan gene flow in Southern Mediterraneans oscillated between 12.9% (Alu loci) and 39.5% (Alu/STR haplotypes), a wide range probably related with the different mutational nature of the markers analyzed and with the effect of repeated homoplasic mutation in STRs.

One might expect the effect of genetic drift to pick up these elements in the Siwa as well, if one is to treat said "sub-Saharan" gene flow level as largely the product of action of random genetic drift in a population of small effective-population size.

The presence of sub-Saharan African traces in the gene pool of North Africans supports the idea of the permeability of the Saharadesert to human migrations as reported in other studies for different kinds of markers (see for example, Plaza et al., 2003; Arredi et al., 2004; Myles et al., 2005; Coudray et al., 2006).

In the above, the authors seem to have no problem in acknowledging the fact that a desert environment, of the Sahara, has not restricted or barred gene flow. This means that these groups are not isolated by the desert; so why couldn't the same logic be approached with regards to the Siwa? It may well be the case, that the Siwa have socio-culturally isolated themselves from other coastal northern African Imazighen groups on their own terms, not to mention the considerable distance between them and the other coastal northern African populations sampled, and has little to do with the desert environment. One will note that even as far as neighboring territories go, which here are apparently European territories bordering the Mediterranean sea, the territory that the Siwa are identified with is relatively more distant from the nearest such territory than those associated with the other coastal northern African populations, respective to their nearest neighbor, This could explain the differentiation in genetic structure and their relative "outlier" position. The authors add:

Interestingly, data from mtDNA and Y-chromosome estimates of sub-Saharan gene flow in North Africa are similar to that obtained from our Alu loci set, a value also concordant with that corresponding to Mozabites in the recent survey of Li et al. (2008) based on more than 500,000 SNPs. The interpretation of the disparity in gene flow estimates according to the kind of marker is difficult, but it might be presumably be related to the different mutation rates of Alu and STRs.

The need to confide in uniparental lineage is not obviously underestimated, but the authors allude once again to the unpredictability characterizing their choice of markers, autosomal markers in the form of Alu sites and flanking tandem repeats at certain designated sites. As we have seen in an earlier piece, the chiming in of homoplasic tendencies in STRs does not dampen this unpredictable character. Of course, since we are dealing with autosomal sites, the question of recombination cannot be avoided. We are assured here, at least with regards to the Alu-STR combinations, that these are perceived to be the types in linkage disequilibrium.

Alu/STR linkage disequilibrium was present in all systems and samples.

This is a sure sign of non-random associations here, which means that the odds against random reshuffling by recombination are high and hence, possibly of some selective pressure advantage of the Alu/STR association. This naturally factors further into that matter about "different mutation rates" and no less, contributes to the unpredictability character of the change in mutation rates in different parts of the genome.

Notwithstanding the lone sub-Saharan sample of Ivory Coast, upon revisiting the matter, one notices that it still managed to give a snapshot of the fact that non-African populations are just representative of a subset of African gene pool:

When STR variation has been analyzed separately in Alu(+) and Alu(-)chromosomes,larger variances are observed in chromosomes carrying the ancestral Alu variant: CD4(+), FXIIIB(-), and DM(+). In humans, the ancestral stage of the CD4 and DM loci is the presence of the Alu insertion, whereas the absence of the insertion is the ancestral stage for the FXIIIB locus (Brook et al., 1992; Nishimura and Murray, 1992; Tishkoff et al., 1996 ). Alu/STR linkage disequilibrium was present in all systems and samples.

The most obvious pattern of haplotype variation is observed in the CD4 system. The ancestral CD4(+) chromosomes show a decreasing pattern of copy number variation from sub-Saharans to Southern and Northern Mediterraneans. Among these latter populations, the 85(+) and 110(+) haplotypes are the most frequent (Supporting Information Table 2). The derived CD4 Alu(-) chromosomes present a lower variation than the ancestral Alu(+) chromosomes, which is statistically significant for Northern Mediterraneans (P < 0.01) and Southern Mediterraneans (P < 0.05), but non-significant for the sub-Saharan sample. This reduction trend is considerable in Northern Mediterranean samples (gene diversity: 0.174 for derived chromosomes vs. 0.554 for ancestral ones), moderate in Southern Mediterraneans (0.458 vs. 0.705), and less marked in sub-Saharans (0.721 vs. 0.778).

The ancestral markers are disproportionately higher in "sub-Saharans", which in this case as we know, is based on that lone sample from the Ivory Coast, and then, they are moderately represented in "southern Mediterraneans", which would be our coastal north African samples here, and least represented of all the groups herein, in the "northern Mediterranean" samples, which here would be the southern European samples. Respectively, greater nucleotide variation is found in "sub-Saharans", as characteristic of the ancestral markers, moderate diversity in coastal northern African, and least diversity in Europe. This seems to find some expression in the general positions assumed by the samples in the plots respective to each marker-format type; in each case, the northern African groups appear to be in the intermediary positions between the African samples in the extremes and the European ones on the other hand. Along the x coordinates of the multidimensional scaling plots provided to us by the authors of the present study, the Ivory Coast sample consistently attains the most extreme position on one end. Please refer back to the plots or maps provided earlier in the body of this post.

Of the derived examples of the Alu-STR clusters, the distributions patterns found in the present study suggest possible "southern Mediterranean" or coastal Northern African origins (or at least, populations ancestral to them) for the following types: CD4 110(-) and DM 107(-)

The highest frequencies of CD4 110(-) and DM 107(-) have been found in the High Atlas region (7 and 5.5%, respectively) of Morocco, reaching polymorphic frequencies in all the North African samples [barring the Mozabites for the CD4 110(-) combination]. They have also been found in the Iberian Peninsula, scattered along the northern Mediterranean shore to Greece and Turkey, and on the main islands of the western Mediterranean (Majorca, Corsica, Sardinia, and Sicily; González-Pérez et al., 2007). The CD4 110(-) haplotype (Flores et al., 2000) andhas also been reported in West Saharans and Mauritanians on five of the seven Canary Islands (Flores et al., 2001), as well as in Adygei from the Northern Caucasus (Tishkoff et al., 1996). Assuming from their frequency distribution that the place of origin of these particular haplotypes is located in the westernmost extreme of North Africa (Fig. 4A,B), their current ample distribution along both shores of the Mediterranean most likely reflects the effect of gene flow across the region since ancient times, even though specific ages cannot be accurately estimated with our data. Similarly, specific Mediterranean haplogroups or clades (U6 and M1b in the mtDNA; EM78 and EM81 in the Y-chromosome) have also been described for these populations and dated in Paleolithic times.

Last but not least, in keeping with pointing out the recurring theme of the lingering onto outdated or outmoded and subjective concepts by the authors of the present study, the following serves as further example:

Concerning Northern Mediterraneans, the gene flow from sub-Saharan Africa was inappreciable for Alu markers and swung from 6 to 15% for the Alu/STR haplotypes data calculations. When gene flow in Northern Mediterraneans was tested, taking Central Europe and Southern Mediterraneans as parental populations, the results were statistically inconsistent, indicating the limited power of our markers to discriminate gene flow within Caucasoid populations. Nonetheless, the distributions of frequencies for the Mediterranean haplotypes CD4 110(-) and DM 107(-) (Fig. 4A,B) are suggestive of gene flow processes across this geographical region.

Such recurring themes throughout different parts of the study do not bode well for the authors at hand.

Nation States of Africa in Antiquity: Did National—GeoPolitical—Boundaries exist Here in Antiquity?

A new feature on this site will be the occasional and recurring posting of matters that come up every now and then in discussions as questions but are otherwise generally considered basic knowledge, under the "Knowledge-base Tool Kit" heading. Our first such topic here, will be on: Nation States of Africa in Antiquity: Did National—GeoPolitical—Boundaries exist Here in Antiquity? In search of answers to this question, turning to antiquated maps will do little to help us, if for no other reason than, that the further back in time one goes, the lesser acquainted with the world's actual geographical breadth and depth were people. Heck, back in the era of humanity's earliest centralized polities known to us today, the average person was more than likely not even conscious of the apparatus of geopolitical unity in terms of affiliation-by-continent, or in various cases, the extent of continents and worlds beyond their own immediate local confines and those of their neighbors. The following is a portion of western Africa, fairly decent-looking—especially given the time or era in question and the relatively narrower scope of people awareness of the world's geographical extent or extremes beyond their own immediate shores and surrounding areas thereof, featuring the well-known sketch of Mansa Musa; presumably one of Spanish origin, dating to the 14th century (ca. 1375):

Click on the image to get a better resolution.

The metmuseum website notes that the original map can be located in France; it site notes: Facsimilie of a map drawn in Spain and dated to 1375, showing the king of Mali holding a gold nugget. Image courtesy of the British Library. The original is held by the Bibliothèque Nationale, Paris.

Below, is a fairly odd representation of the northern portion of Africa and neighboring areas, reportedly of some European [southern European] origin and dating to the Medieval era...

Click on the image to get a better resolution.

Below, we have a 15th century map by Giovanni Leardo:

Click on the image to get a better resolution.

A circa 17th century rendition of Africa...

Click on the image to get a better resolution.

What's notable about all these mapping manifestations of world geography, is that they all reflect different perceptions by different observers, and at different points in time. Therefore any assessment about any early maps of the sorts exemplified herein, while serving useful historical purpose, can only be subjective in reality, in accordance to the observer who created or authored the maps in question; they are subjective, because they would have been impacted by the limitations of the observers then knowledge base, whose views in most cases, would have been shaped by the world of the era they belonged to. It is safe to say that the different shapes of the maps above exemplify this. Therefore, the "accuracy of the maps" in question, can only reflect the scope of knowledge of the observer, and their intent in creating said maps. Furthermore, none of these maps reflect the geopolitical status quo of complexes traced considerably further back into antiquity, like say—the ancient Egyptian era, which had long gone by then. Any maps of the African continent or at least portions of it in the ancient Egyptian period, would have been even cruder than those shown above, because folks' knowledge of the world's geography was even more limited than that of their counterparts who proceeded them much later in time, in the "medieval" and contemporary times. However, one need not have these maps to ascertain that there were nation states in antiquity that had their own political boundaries, before the European imperialism that gained momentum after the 15th century. As noted here before, we have tangible evidence to this end, in terms of militarized border fortifications in the ancient Egyptian case. Furthermore, in the so-called medieval period, complexes like the Songhai empire, or even ancient Mali, apparently had their own political borders, which other western African complexes to their north for example, would have had to recognize, and could therefore only infringe on their sovereignty by use of force, if they had the means to. Recalling the harassment meted out to the ancient Ghanaian state by armed Tamazigh-speaking semi-nomads (reportedly affiliated with the Almoravid group) of the Sahel; what was all that about? Ancient Ghana had cavalry—why? What about the invasion of Songhai by the ancient Moroccan Kingdom under al Mansur. Again, it had to take force, for the Moroccan kingdom to lay any claim on territory under the Songhai polity, precisely because prior to that, Songhai would have been recognized as a sovereign socio-political entity, with borders that needed to be respected. Same assessments could be made for the conflicts between the Kushites and the ancient Egyptians, and between the Romans and the Kushites over Nile Valley territory, and so forth. Otherwise, there would be no need for such conflict; people can just come and go as they pleased. Hopefully, the intended point here is clear. An empire without borders has never existed—at least not to the knowledge of the present author.

Friday, October 23, 2009

At basic, one might surmise that "behaviorally modern" implies behavior that contemporary human populations can instantly relate to. However, precisely, what does it mean to be "behaviorally modern", as it relates to human prehistory; do the players in the academia use this term in the same context or apply it on the basis of a set scholarly code? For certain, "behaviorally modern" has been a recurring terminology in a number of articles over the years. Recounting one such appearance, here is a piece from Reuters dating back to early 2006 or so, titled Radiocarbon review rewrites European prehistory:

The ancestors of modern man moved into and across Europe, ousting the Neanderthals, faster than previously thought, a new analysis of radiocarbon data shows.Rather than taking some 7,000 years to colonize Europe from Africa, the reinterpreted data shows the process may only have taken 5,000 years, scientist Paul Mellars from Cambridge University said in the science journal Nature on Wednesday...Populations of anatomically and behaviorally modern humans **first appeared** in the near eastern region some 45,000 years ago and slowly expanded into southeastern Europe.

More recently, the matter cropped up in a Science Daily article of August 4th, 2009; the article noted:

...there has been a longstanding disagreement whether humans began to increase in number as a result of innovative technologies and/or behaviors formulated by hunter-gatherer groups in the Late Pleistocene, or with the advent of agriculture in the Neolithic...

Well, what does molecular genetics, a comparatively younger field have to say about this? The Science Daily article in question proceeds to tell the audience this:

ScienceDaily (Aug. 4, 2009) — Genetic evidence is revealing that human populations began to expand in size in Africa during the Late Stone Age approximately 40,000 years ago. A research team led by Michael F. Hammer (Arizona Research Laboratory's Division of Biotechnology at the University of Arizona) found that sub-Saharan populations increased in size well before the development of agriculture.

One can see from Science Daily's report, that molecular genetics answers the pressing matter of the causative behind the initial explosion(s) of human population size, which is torn between the aforementioned opposing factions of academia. However, that "magic date" of ca. 40 k or 45 k years ago shows its head again. What is up with the persistent latching onto that date or time frame? One would think that in concordance to archaeological finds, not to mention that of DNA sequencing just now talked about, that academia would have by now moved on from such 'rigid' thinking! Upon revisiting that Science Daily piece,...

...there has been a longstanding disagreement whether humans began to increase in number as a result of innovative technologies and/or behaviors formulated by hunter-gatherer groups in the Late Pleistocene, or with the advent of agriculture in the Neolithic...

...and then thinking back to such articles, like for example...

—Oldest Jewelry? "Beads" Discovered in African Cave [Blombos finds]

— Tiny Ancient Shells -- 80,000 Years Old -- Point To Earliest Fashion Trend [finds at 4 sites in Morocco]

—African Bone Tools Dispute Key Idea About Human Evolution When Did Modern Behavior Emerge in Humans?

Not to mention one about Homo Erectus "urbanization" in northern and eastern Africa.

...one gets an idea of the recurring theme of these finds, which is that the thesis centered on the 'magical' era of a supposed "unprecedented" sudden burst of human "intellectual" ingenuity around 45 ky or 40 ky ago or so is no longer tenable. Getting back to the question posed at the beginning of this post, pertaining to what "behaviorally modern" means and whether it has been framed according to discretion of individuals or according to a settled academic standard, let's take a look back at one of the articles listed above—the one published by National Geographic in 2004, titled Oldest Jewelry? "Beads" Discovered in African Cave. In a segment of that article titled "Weighing the Evidence", this is said of one observer's (by the name of Bower) reaction to Blombos Cave bead findings:

When is a bead a bead? The two ostrich-eggshell beads found at the Serengeti site are unquestionably beads, but questions pertaining to the accuracy of their dating at 70,000 years old remain. By contrast, the date of the Blombos artifacts is fairly certain, but some question exists as to whether they are actually beads."The photographs [of the Blombos beads] look pretty convincing, but I'd like to see them in the flesh," Bower said. "A lot of shells like that have perforations, where they've been dropped by seagulls or occur through natural agencies. I'm cautiously convinced; it doesn't surprise me they occurred in a middle Stone Age context, since we found [beads] in Serengeti also."

Another observer...

The presence of beads, whether used as trade items, to convey group status, or to identify group members or relationships within a group suggests some form of language existed, says Henshilwood, who is affiliated with the University of Bergen, Norway, and the State University of New York."What the beads might symbolize is unknown, but it does imply that there had to be some means of communicating meaning, which plausibly is language," Henshilwood said.

"Everyone knew what it meant, just as today if you're wearing Gucci sunglasses or a diamond tennis bracelet, there's a message being put out."

Notwithstanding differences in the circumstances under which they were made, the observations of the two observers above converge, where viewing the artifacts as "beads" is concerned; that is, an item of "symbolism" and thereof with cultural value and message, something that populations can relate to "today". Contrast the two above-mentioned observers with the next one...

Richard Klein, an anthropologist at Stanford University who has worked extensively at dig sites in South Africa, is a major proponent of the idea that modern behavior appeared rapidly, around 45,000 years ago, possibly as the result of a genetic change that facilitated our use of language. He is not convinced that the shells found at Blombos are actually beads."The holes are irregular and look fresh," Klein said.

"We need to know why [the investigators at the Blombos site] think they were made by human hand and how they think they were made—were the holes punched out, did they file them, were they drilled out? Shell beads are very common in late Stone Age coastal sites, and you can see they're clearly modified as beads.

"There are ten sites in South Africa that have been excavated, and at only one do we find this kind of evidence for precocious behavior. I don't think the case has been clearly made yet that these are beads."Klein also notes that the history of archaeology is littered with examples where later deposits of archaeological artifacts have slumped into older layers.The isolated finds from middle Stone Age sites in Africa, even if correctly dated, don't necessarily indicate widespread "modern" behavior.

"don't necessarily indicate widespread "modern" behavior"? Perhaps one might figure that Klein is one of those personalities who suffer from the aforementioned "rigid thinking"—despite findings piling up which necessitate modification in one's thinking, bent on defending his vision of the 45k "magical moment" of human ingenuity for the first time in prehistory, spurred by some genetic mutation. This is how archaeologist Donald Johanson described Klein's viewpoint, consistent with the Science Daily article on the same matter revolving around some unprecedented "genetic change",...

"Klein, on the other hand, proffers the notion that it was probably a biological change brought about by mutations that played the key role in the emergence of behaviorally modern humans. His biologically based explanation implies that a major neural reorganization of the brain resulted in a significant enhancement in the manner in which the brain processed information.This is a difficult hypothesis to test since brains do not fossilize. But it is significant that no changes are seen in the shape of the skulls between earlier and later Homo sapiens."

But...

"It can only be surmised from the archaeological record, which contains abundant evidence for ritual and art, that these Upper Paleolithic/Late Stone Age peoples possessed language abilities equivalent to our own. For many anthropologists this represents the final evolutionary leap to full modernity."

Indeed, Klein's thesis of a sudden genetic mutation event as the causative in the "magical time frame" of ca 45k years ago cannot be discerned from fossil record, but it is precisely from such material, along with other aspects of archaeological index, that make it possible to discern the extent of human ingenuity. On another hand, one might say that perhaps Klein is to be forgiven for not being mindful of all the information now available at the time the cited comments here were made. Well, despite the fact that Klein must have been aware of the Serengeti finds in Tanzania that were also mentioned in the article under discussion, which also happened to be made up of beads, not to mention the matter of the "African Bone Tools", he still had himself convinced that these were not indicative enough of widespread "precocious behavior". In keeping with the matter at hand, Klein attempts to equate the Blombos finds with Michelangelo's "creativity", presumably as an "isolated" undertaking of an individual...

"You could have the prehistoric equivalent of a Michelangelo," Klein said. "An individual far ahead of his time, able to come up with innovative ideas that the rest of society doesn't adopt."

In making that analogy, it appears that it hadn't dawned on Klein that Michelangelo was a product of a society that already had 'culture' in place, i.e. culture with its own collections of symbolism or messages encoded through conduct and material. His "creativity" was an outgrowth of 'culture(s)' [beliefs, traditions, social order and conduct, social conditioning from childhood and so forth] that he was immersed in. It is against this backdrop, that this "creativity" was appreciated and deemed to have "meaning" in the first place; without that preexisting cultural background, Michelangelo's "creativity" would have ceased being viewed as a "necessity" [we shall shortly take a look at Henshilwood's factoring in the different environments and their associated various guises of necessity as possible influences in human behavior development]. Getting back to those "excuses" that could be made for Klein's shortsightedness, the aforementioned Henshilwood was cited by the National Geographic article rationalizing as follows...

The Coastal AdvantageHenshilwood has a different theory to explain why evidence of symbolic thinking or "modern" behavior shows up in only some of the middle Stone Age sites, rather than all of them."The answer could be that it's not a behavior that's necessarily required everywhere," he says. Early modern humans living in a region with plenty of land animals, for instance, wouldn't be motivated to develop specialized tools to catch fish.In addition, Henshilwood thinks the people at Blombos may have had a nutritional advantage. "We know today that fish is brain food," he said. "It's possible that people living in coastal regions just had a lot more going on. Remember, modern humans followed the coastline and reached Australia about 60,000 years ago, and they had to figure out how to build a boat to get there."He says the "creative explosion" that took place around 45,000 years ago could be merely the result of facing new environmental and social pressures. Such pressures might have included an increase in population and competition with other species outside of Africa, like the Neandertals, who had occupied Europe for several hundred thousand years.

Note Henshilwood's factoring in of environmental influence and associated necessity born out of that. Again, however, we come across this need for accommodating the so-called magical era [45ky] of 'creative explosion'. A case can be made that there were other hominids in Africa as well, whom the then outgoing Africans had to confront before minding about remnants of earlier OOA migrants outside of the continent. Surviving on the continent was no cakewalk by any means, and perhaps, the reason for human expansions elsewhere to begin with, if not in part! Could the tunnel vision-like-approach of this "magic era of creative explosion" viewpoint be in anyway affiliated with the advent of the arrival of ancestors of Europeans in the European sub-continent; in other words, "the magic era of creative explosion to coincide with the arrival of the immediate ancestors of contemporary Europeans", which is generally placed within the vicinity of the time frame of 40k to 42k or between 40k and 45k years ago? Such link at the moment requires unequivocal substantiation that needs to be further investigated, but Donald Johanson for his part, makes it a point to inform his audience that this "creative explosion" took place first in Africa before spreading elsewhere:

The archaeological picture changed dramatically around 40-50,000 years ago with the appearance of behaviorally modern humans. This was an abrupt and dramatic change in subsistence patterns, tools and symbolic expression. The stunning change in cultural adaptation was not merely a quantitative one, but one that represented a significant departure from all earlier human behavior, reflecting a major qualitative transformation. It was literally a "creative explosion" which exhibited the "technological ingenuity, social formations, and ideological complexity of historic hunter-gatherers."7 This human revolution is precisely what made us who we are today.

The appearance of fully modern behavior apparently occurred in Africa earlier than anywhere else in the Old World, but spread very quickly, due to population movements into other geographical regions.

The Upper Paleolithic lifestyle, as it was called, was based essentially on hunting and gathering. So successful was this cultural adaptation that until roughly 11,000 years ago, hominids worldwide were subsisting essentially as hunter-gatherers.In the Upper Paleolithic of Eurasia, or the Late Stone Age as it is called in Africa, the archaeological signature stands in strong contrast to that of the Middle Paleolithic/Middle Stone Age. It was characterized by significant innovation:

a remarkable diversity in stone tool types

tool types showed significant change over time and space

artifacts were regularly fashioned out of bone, antler and ivory, in addition to stone

stone artifacts were made primarily on blades and were easily classified into discrete categories, presumably reflecting specialized use

burials were accompanied by ritual or ceremony and contained a rich diversity of grave goods

living structures and well-designed fireplaces were constructed

hunting of dangerous animal species and fishing occurred regularly higher population densities

abundant and elaborate art as well as items of personal adornment were widespread

raw materials such as flint and shells were traded over some distances

Homo sapiens of the Upper Paleolithic/Late Stone Age was quintessentially modern in appearance and behavior. Precisely how this transformation occurred is not well understood, but it apparently was restricted to Homo sapiens and did not occur in Neanderthals. Some archaeologists invoke a behavioral explanation for the change. For example, Soffer11 suggests that changes in social relations, such as development of the nuclear family, played a key role in bringing about the transformation.

Johanson too appears to have fallen victim to the 40ky ago "magic era of modern behavior" mentality, urging him to match his lower-end time frame limit for the initiation of this event with the 40ky ago date as opposed to going for a substantially higher lower-end time frame right off the bat, but less stingy when it comes to entertaining the possibility of a considerably higher time frame, as his allowable "upper-end" 50ky time frame indicates. Bower, on the other hand, had shared his own views on what "modern behavior" means:

"I hate the use of the word 'modern,'" Bower says. "Modern behavior is talking on the telephone. Clearly that's not what humans were doing a hundred thousand years ago."

Be that as it may, his opinion on what constitutes "modern behavior", what Bower says next may well be instructive; quote:

Emerging evidence suggests that aspects of human technology are now strung out way back in time. Blombos has bone points—you have the famous bone harpoons at Katanga [Central Africa, about 90,000 years old]—long before the "creative explosion of 40,000 to 45,000 years ago." "I'm inclined to think we should get rid of the whole concept of 'modern' behavior," Bower said.

Instructive; why? It could serve an instructive purpose, because quite simply, Bower's comment here appears to be the more accommodating one of all those professed by the various personalities thus far examined, to the accumulative property of the field of archaeology. Indeed, as we examine published material on additional and more recent finds in archaeology, while mindful of developments of other fields like molecular genetics, it becomes ever so harder to defend rigid concepts like the "sudden explosive event of creativity at around 40k or 45k years ago". This can be demonstrated from a series of publications, fairly recent ones as of the writing of this post, expanding on the small list of examples posted near the beginning of this post; consider:

"Our illumination of the heat treatment process shows that these early modern humans commanded fire in a nuanced and sophisticated manner," says lead author Kyle Brown, a doctoral candidate at the University of Cape Town, and field and lab director in Mossel Bay, South Africa, for ASU's Institute of Human Origins."We show that early modern humans at 72,000 years ago, and perhaps as early as 164,000 years ago in coastal South Africa, were using<carefully controlled hearths in a complex process to heat stone and change its properties, the process known as heat treatment," explains Brown.

"Heat treatment technology begins with a genius moment – someone discovers that heating stone makes it easier to flake," says Curtis Marean, project director and a co-author on the paper.Marean is a paleoanthropologist with the Institute of Human Origins and a professor in the School of Human Evolution and Social Change at Arizona State University's College of Liberal Arts and Sciences."This knowledge is then passed on, and in a way unique to humans, the technology is slowly ratcheted up in complexity as the control of the heating process, cooling and flaking grows in sophistication," Marean says.This creates a long-chain technological process that the researchers explain requires a complex cognition, and probably language, to learn and teach.The heating transformed a stone called silcrete, which was rather poor for tool making, into an outstanding raw material that allowed the modern humans to make highly advanced tools.

...Symbolic behavior and modern human origins"Our discovery shows that these early modern humans had this complex cognition," Brown says."This expression of cognitive complexity in technology by these early modern humans on the south coast of South Africa provides further evidence that this locality may have been the origin location for the lineage that leads to all modern humans, which appeared between 100,000 and 200,000 years ago in Africa," explains Marean."There is no consensus as to when modern human behavior appears, but by 70,000 years ago there is good evidence for symbolic behavior," he says. "Many researchers are looking for technological proxies for complex cognition, and heat treatment is likely one such proxy.

"Prior to our work, heat treatment was widely regarded as first occurring in Europe at about 25,000 years ago," Marean says. "We push this back at least 45,000 years, and, perhaps, 139,000 years, and place it on the southern tip of Africa at Pinnacle Point."The African location was at the center of another discovery by Marean – the documentation of the earliest evidence for exploitation of marine foods and modification of pigments– reported in the Oct. 17, 2007, journal Nature."Combined, these results sharply advance our knowledge of modern human origins, and show that something special in human cognition was happening on the coastline of South Africa during this crucial final phase in human origins," Marean says.He adds that some time around 50,000 to 60,000 years ago, "these modern humans left the warm confines of Africa and penetrated into the colder glacial environment of Europe and Asia, where they encountered Neanderthals."By 35,000 years ago these Neanderthal populations were mostly extinct, and modern humans dominated the land from Spain to China to Australia," Marean says.

"The command of fire, documented by our study of heat treatment, provides us with a potential explanation for the rapid migration of these Africans across glacial Eurasia – they were masters of fire and heat and stone, a crucial advantage as these tropical people penetrated the cold lands of the Neanderthal," says Marean.Link

The controlled use of fire was a breakthrough adaptation in human evolution. It first provided heat and light and later allowed the physical properties of materials to be manipulated for the production of ceramics and metals. The analysis of tools at multiple sites shows that the source stone materials were systematically manipulated with fire to improve their flaking properties. Heat treatment predominates among silcrete tools at ~72 thousand years ago (ka) and appears as early as 164 ka at Pinnacle Point, on the south coast of South Africa. Heat treatment demands a sophisticated knowledge of fire and an elevated cognitive ability and appears at roughly the same time as widespread evidence for symbolic behavior. - Abstract endsLink

From Marean et al 2007

Evidence of early humans living on the coast in South Africa, harvesting food from the sea, employing complex bladelet tools and using red pigments in symbolic behavior 164,000 years ago, far earlier than previously documented, is being reported in the journal Nature.The international team of researchers reporting the findings include Curtis Marean, a paleoanthropologist with the Institute of Human Origins at Arizona State University and three graduate students in the School of Human Evolution and Social Change.

"Our findings show that at 164,000 years ago in coastal South Africa humans expanded their diet to include shellfish and other marine resources, perhaps as a response to harsh environmental conditions," notes Marean, a professor in ASU's School of Human Evolution and Social Change. "This is the earliest dated observation of this behavior."After decades of debate, paleoanthropologists now agree the genetic and fossil evidence suggests that the modern human species -- Homo sapiens -- evolved in Africa between 100,000 and 200,000 years ago.Migrating along the coast"Generally speaking, coastal areas were of no use to early humans -- unless they knew how to use the sea as a food source" says Marean. "For millions of years, our earliest hunter-gatherer relatives only ate terrestrial plants and animals. Shellfish was one of the last additions to the human diet before domesticated plants and animals were introduced."Before, the earliest evidence for human use of marine resources and coastal habitats was dated about 125,000 years ago.

"Our research shows that humans started doing this at least 40,000 years earlier. This could have very well been a response to the extreme environmental conditions they were experiencing," he says."We also found what archaeologists call bladelets -- little blades less than 10 millimeters in width, about the size of your little finger," Marean says. "These could be attached to the end of a stick to form a point for a spear, or lined up like barbs on a dart -- which shows they were already using complex compound tools. And, we found evidence that they were using pigments, especially red ochre, in ways that we believe were symbolic," he describes.

"Coastlines generally make great migration routes," Marean says. "Knowing how to exploit the sea for food meant these early humans could now use coastlines as productive home ranges and move long distances." "This evidence shows that Africa, and particularly southern Africa, was precocious in the development of modern human biology and behavior. We believe that on the far southern shore of Africa there was a small population of modern humans who struggled through this glacial period using shellfish and advanced technologies, and symbolism was important to their social relations. It is possible that this population could be the progenitor population for all modern humans," Marean says.

ScienceDaily (Aug. 27, 2009) — Shell beads newly unearthed from four sites in Morocco confirm early humans were consistently wearing and potentially trading symbolic jewelry as early as 80,000 years ago. These beads add significantly to similar finds dating back as far as 110,000 in Algeria, Morocco, Israel and South Africa, confirming these as the oldest form of personal ornaments. This crucial step towards modern culture is reported this week in the Proceedings of the National Academy of Sciences (PNAS).

Subtext reads, courtesy of Science Daily: Perforated Nassarius gibbosulus from archaeological layers dated to between 73,400 and 91,500 years ago at Taforalt. (Credit: Image courtesy of d'Errico/Vanhaeren).Click on the image for higher resolution.

A team of researchers recovered 25 marine shell beads dating back to around 70,000 to 85,000 years ago from sites in Morocco, as part of the European Science Foundation EUROCORES programme 'Origin of Man, Language and Languages'. The shells have man-made holes through the centre and some show signs of pigment and prolonged wear, suggesting they were worn as jewelry.Across all the locations shells were found from a similar time period from the Nassarius genus. That these shells were used similarly across so many sites suggests this was a cultural phenomenon, a shared tradition passed along through cultures over thousands of years. Several of the locations where shells have been found are so far inland that the shells must have been intentionally brought there.

"Either people went to sea and collected them, or more likely marine shell beads helped create and maintain exchange networks between coastal and inland peoples. This shows well-structured human culture that attributed meaning to these things," said Francesco d'Errico, lead author and director of research at the French National Centre for Scientific Research (CNRS). "Organised networks would also assist trading of other items, as well as genetic and cultural exchange – so these shells help reveal the connections between cognition and culture."

For scientists, beadworks are not simply decoration, they also represents a specific technology that conveys information through a shared coded language. It indicates more advanced thinking and the development of modern cultural traits, giving clues to how such innovative behaviors might link to the spread of humans out of Africa. "The early invention of the personal ornament is one of the most fascinating cultural experiments in human history," d'Errico continued. "The common element among such ornaments is that they transmit meaning to others. They convey an image of you that is not just your biological self."

Note here too, the authors could not resist openly acknowledging past attempts at making "modern behavior" only coincidental with the colonization of Europe by the ancestors of contemporary Europeans; see—they continue with:

Until recently the invention of personal ornaments was thought to coincide with the colonisation of Europe some 40,000 years ago, linking advanced cognitive capacity to early ["European-associated"; present author's emphasis]human dispersal. Yet this changed with the 2006 discovery of shell beads in Africa and the Near East dating back 35,000 years earlier, showing that symbolic thinking emerged more gradually through human evolution.Curiously, shell beads disappear from the archaeological record in Africa and the Near East 70,000 years ago, along with other cultural innovations such as engravings on ochre slabs, and refined bone tools and projectile points. They reappear in different forms up to 30,000 years later, with personal ornaments simultaneously re-emerging in Africa and the Near East, and for the first time in Europeand Asia. This may reflect an entirely new and independent phase of population growth with previously unseen innovations allowing a more efficient exploitation of a wider variety of environments.The temporary disappearance of cultural innovations could well be linked to population decreases during a long period of harsher climate conditions 60,000 to 73,000 years ago. This would have isolated populations, disrupting social and exchange networks.

This study was part of a broad network of 21 research projects and 44 individual research teams from 12 European countries forming the European Science Foundation EUROCORES programme 'Origin of Man, Language and Languages' (OMLL). This highly interdisciplinary collaborative action brought together scientists from a wide range of disciplines including genetics, linguistics, anthropology, archaeology, neurophysiology or cognitive sciences. Dr Eva Hoogland, EUROCORES coordinator for the cognitive sciences at the European Science Foundation said: "This study presents a very good example of the groundbreaking results that can be gained from an interdisciplinary environment. Some questions, such as those concerning the interconnections between human cognition and culture, can only be addressed if scientists of varying backgrounds join forces. As witnessed by this study, this opens up new avenues for research when it happens on a structural basis, by leading scientists from across Europe."This research was also supported with funding from the Natural Environment Research Council, the British Academy and Oxford University in the UK and the Max Planck Society in Germany.

For more reading, try this:ScienceDaily (May 7, 2009) — A team of archaeologists has uncovered some of the world’s earliest shell ornaments in a limestone cave in Eastern Morocco. The researchers have found 47 examples of Nassarius marine shells, most of them perforated and including examples covered in red ochre, at the Grotte des Pigeons at Taforalt. The fingernail-size shells, already known from 82,000-year-old Aterian deposits in the cave, have now been found in even earlier layers. While the team is still awaiting exact dates for these layers, they believe this discovery makes them arguably the earliest shell ornaments in prehistory. The shells are currently at the centre of a debate concerning the origins of modern behavior in early humans.

Many archaeologists regard the shell bead ornaments as proof that anatomically modern humans had developed a sophisticated symbolic material culture. Up until now, Blombos cave in South Africa has been leading the ‘bead race’ with 41 Nassarius shell beads that can confidently be dated to 72,000 years ago. Aside from this latest discovery unearthing an even greater number of beads, the research team says the most striking aspect of the Taforalt discoveries is that identical shell types should appear in two such geographically distant regions. As well as Blombos, there are now at least four other Aterian sites in Morocco with Nassarius shell beads. The newest evidence, in a paper by the authors to be published in the next few weeks in the Journal of Quaternary Science Reviews, shows that the Aterian in Morocco dates back to at least 110,000 years ago...

Research team leader, Professor Nick Barton, from the Institute of Archaeology at the University of Oxford, said: ‘These new finds are exciting because they show that bead manufacturing probably arose independently in different cultures and confirms a long suspected pattern that humans with modern symbolic behavior were present from a very early stage at both ends of the continent, probably as early as 110,000 years ago.’ Also leading the research team Dr Abdeljalil Bouzouggar, from the Institut National des Sciences de l’Archéologie et du Patrimoine in Morocco, said: ‘The archaeological and chronological contexts of the Taforalt discoveries suggest a much longer tradition of bead-making than previously suspected, making them perhaps the earliest such ornaments in the world.’...

The complete publication is available elsewhere on the net.Recent findings about Homo Erectus settlements in Africa also raise a plausible question: If "urbanization" or "sedentary settlement" is a sign of "precocious behavior", then would that not apply to these hominids and extend such behavioral pattern even further in time, dating beforethe appearance of "anatomically modern humans"?If so, it would make modern humans less unique, wouldn't it?Well, we learn from archaeologist Prof. Helmut Ziegert of Hamburg University, about the presence of huts and sedentary life dating back to ca. 400ky to 200ky ago, linked not to anatomically modern humans, whom the findings either predate or at least coincides with their first emergence, but to the Homo Erectus; read about it here:

MINERVA JULY/AUGUST 2007

Jerome M. Eisenberg, Ph.D. and Dr Sean KingsleyFor decades archaeologists have rightly respected the Neolithic period c. 8500 BC as a revolutionary era of the most profound change, when the wiring of mankind's brain shifted from transient hunter-gathering to permanent settlement in farming communities. Hearths, temples, articulated burials, whistling 'wheat' fields and security replaced the uncertain ravages of seasonal running with the pack. Or so stereotypes maintain. Now, from the remote shores of Budrinna on Lake Fezzan in Libya, and Melka Konture on the banks of the River Awash in Ethiopia, a series of stunning discoveries are set to challenge the originality of the Neolithic Revolution.

After 39 years of surveys and excavations, Professor Helmut Ziegert of Hamburg University presents his results as a world exclusive in Minerva (pp. 8-9). In both African locations he has discovered huts and sedentary village life dating between an astonishing 400,000 and 200,000 Before Present - if correct, literally a quantum leap in our understanding of man's evolution. Near aquatic resources, and not alongside agricultural fields, Professor Ziegert contests that our ancestors settled down for the first time in small communities of 40-50 people. At the heart of this new Lower Palaeolithic 'out of Africa' village theory are two world-changing ideas. First, that Homo erectus, Upright Man, had far more modernistic tendencies than previously believed; and second, that as unique as the farming villages of Jericho in the West Bank and Catalhoyük in Turkey are, their occupants were not the brains behind the origins of sedentism.

The innovative capacity of Homo erectus has challenged scholars for decades and remains a scholarly cauldron. Anthropologists such as Richard Leakey have long insisted that Upright Man was socially more akin to modern humans than to his primitive predecessors because the increased cranial capacity coincided with more sophisticated tool technology. Other scientists contend that Homo erectus was sufficiently advanced to have even mastered maritime transport. Yet both this assertion and the very idea that he ever got to grips with controlled fire are still considered controversial.

Only three years ago, however, Nira Alperson of the Hebrew University in Jerusalem discovered the oldest evidence of fire management at Gesher Benot Ya'aqov on the banks of the Jordan River in Israel's northern Galilee. The team analysed over 50,000 pieces of wood and nearly 36,000 flints from two hearths associated with a Homo erectus settlement dating back 790,000 years. More contentiously, Robert Bednarik is convinced that Upright Man ushered in the dawn of trans-ocean travel between 900,000 and 800,000 years ago as part of a wider revolution, usually attributed to the anatomically modern Homo sapiens, that included communicating with a spoken language and eventually carving and painting art 400,000 to 300,000 Before Present.

To test his theory, Bednarik built a 17.5m long, 2.8-ton bamboo raft, Nale Tasih 4, and crossed the 29km-wide stretch of sea from the east coast of Bali to the neighbouring island of Lombok. The results have convinced Bednarik that 'Between 400,000 and 200,000 years ago, hominins are also known to have crossed to at least two islands in Europe, Corsica, and Sardinia. This is soundly demonstrated, but in addition it is possible that much earlier they managed to cross the Strait of Gibraltar. Unfortunately, that cannot be proved conclusively, because the alternative of reaching Europe by land has always existed'. Stone Age 'seafaring appears to have been possible', agrees anthropologist Tim Bromage of Hunter College of the City University of New York, who has identified 30cm-wide South-east Asian bamboo as providing a versatile material for building rafts with simple stone tools.

So, Professor Ziegert's 'Out of Africa' aquatic model for the rise of village life in the Lower Palaeolithic does not emerge out of a cultural and intellectual void. As a veteran of over 81 archaeological surveys and excavations from Germany to Ecuador, ranging in date from the Lower Palaeolithic to the Islamic period, Ziegert is nothing if not scientifically cautious, which makes the current revelation all the more exciting. Between 2007 and 2010 he will be back in the field, returning to Budrinna and Melka Konture to fine-tune his life's work. To delve in greater depth into the mystery of the ecology, function, structure, and economy of these villages, he plans to search out cemeteries (complementary signs of fixed settlement) and use potassium argon isotopic dating, stratigraphy, and tool typology to measure the ebb and flow of village life in this dizzy, distant prehistoric past. - Ends

All the notes touched upon here demonstrate if nothing else, that the term "behaviorally modern" along with its associated "magical era of 40ky or 45 ky ago explosion" that happens to be coincidental with the colonization of Europe by anatomically modern humans are far more loaded concepts than the primary proponents make them out to be. These notes show that "behaviorally modern" doesn't even appear to have a consistent meaning across academia, nor does the emerging and changing archaeological record hold the tunnel vision-oriented approach of the "magical era of creative human explosion around 40ky or 45ky ago" ideological camp tenable any longer. It is not unreasonable to surmise that the said tunnel vision-like-approach may have something to do with the urge or desire to make the colonization of Europe by anatomically modern humans an event more extraordinary than it actually was, by matching up its time frame closely with a supposed "unprecedented" change in human behavior, spurred by some "unprecedented genetic mutation", a "very celebrated" part of which the earliest common recent ancestors of contemporary European would undoubtedly be made, within segments of "Western" academia. *Keep an eye on possible future updates.
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*References:

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